Which of the following actions is NOT a function of hormones?

Hormones are signaling molecules that are crucial for various physiological processes in the body. While they perform numerous roles, one of their primary functions is to facilitate communication between different cells, allowing for coordination of various bodily functions. Hormones travel through the bloodstream to target organs and tissues, influencing various processes such as growth, metabolism, and homeostasis.

Regulating metabolism is an important function of hormones, as they help control the energy utilization and storage in the body. For instance, insulin plays a vital role in glucose metabolism, while thyroid hormones are significant in regulating basal metabolic rate.

Promoting muscle growth is also a function of certain hormones, particularly anabolic hormones like testosterone and growth hormone, which are involved in the stimulation of muscle protein synthesis and tissue development.

On the other hand, the action of "feeding on blood" does not correlate with any hormonal function. This phrase might suggest a behavior characteristic of certain animals, such as vampires or parasites, but it is not related to how hormones operate within biological systems. Hormones do not consume blood nor engage in any direct physical action like feeding. Thus, identifying "feeding on blood" as not being a function of hormones aligns with the understanding of what hormones are and what they do in the body.